The present invention relates generally to data communication and more specifically to the provision of supervisory signaling and power over the same twisted pairs as are employed for data signaling in accordance with a high speed data communication protocol.
Data communication over 100BASE-T and 1000BASE-T in accordance with the Ethernet protocols are well known. Using these protocols, Ethernet signals may be transmitted over twisted pairs such as CAT5, CAT 5e, CAT6 or any similar cable that includes four twisted pairs. The twisted pairs may be shielded or unshielded. A separate Ethernet signal is typically transmitted over each of the twisted pairs as a differential signal. In a 1000BASE-T Ethernet system, the lowest frequency that must be passed over an Ethernet pair unimpaired is 100 kHz.
While the use of cabling such as CAT5 permits the transmission of four Ethernet signals over the four twisted pairs, numerous circumstances arise in which it would be desirable to provide additional signaling capabilities and to supply power to a remote device without incurring the expense associated with the procurement and installation of additional wiring.